There are a couple of older packages remaining ....... version 4.6.5
I would suggest doing a search in Synaptic for 4.6.5
and change the 'Look in' line to 'Version' from the drop down options.
Remove any 4.6.5
packages and install any equivalent 4.9.5
packages not already installed.
plasma-applet-didyouknow is the only 4.6.5 package showing up in a search in Synaptic here .... and is not installed.